Looks like everywhere except where GFCI required.

Chapter 2 Wiring and Protection :: ARTICLE 210 Branch Circuits :: I. General Provisions

70-2008:210.12(210.1-210.18)702008210.12 Arc-Fault Circuit-Interrupter Protection.

(A) Definition: Arc-Fault Circuit Interrupter (AFCI). A device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected.

(B) Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc-fault circuit interrupter, combination-type, installed to provide protection of the branch circuit.

Changed From 2005
•210.12(B): Expanded AFCI protection requirements to include all outlets supplied by 15- and 20-ampere, 120-volt branch circuits installed in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas, and deleted effective date on use of branch/feeder AFCIs.

FPN No. 1: For information on types of arc-fault circuit interrupters, see UL 1699-1999, Standard for Arc-Fault Circuit Interrupters.

FPN No. 2: See 11.6.3(5) of NFPA 72®-2007, National Fire Alarm Code®, for information related to secondary power supply requirements for smoke alarms installed in dwelling units.

FPN No. 3: See 760.41(B) and 760.121(B) for power-supply requirements for fire alarm systems.

Exception No. 1: Where RMC, IMC, EMT or steel armored cable, Type AC, meeting the requirements of 250.118 using metal outlet and junction boxes is installed for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, it shall be permitted to install a combination AFCI at the first outlet to provide protection for the remaining portion of the branch circuit.

Changed From 2005
•210.12(B) Exception No. 1: Revised exception to permit branch-circuit conductors without AFCI protection from the panelboard to the first outlet if conductors are installed in rigid RMC, IMC, EMT, or steel AC cable for that portion of the circuit and the remaining portion is protected by a combination AFCI.

Exception No. 2: Where a branch circuit to a fire alarm system installed in accordance with 760.41(B) and 760.121(B) is installed in RMC, IMC, EMT, or steel armored cable, Type AC, meeting the requirements of 250.118, with metal outlet and junction boxes, AFCI protection shall be permitted to be omitted.

Changed From 2005
•210.12(B) Exception No. 2: Added exception to permit omission of AFCI protection for conductors of an individual branch circuit supplying a fire alarm system that are installed in RMC, IMC, EMT, or steel AC cable.